Expansion joints covered by this specification are intended for steam, water, oil, or gas piping services which require the absorption of movement resulting from the thermal expansion of piping or other factors.

Slip-tube expansion joints are suitable for pressure-temperature service conditions in accordance with the ratings prescribed by the ASME piping standards for the type of materials used.

No expansion joint listed in this specification is intended for operation without adequate provision for guiding and anchoring the system in accordance with the manufacturer's recommendations and in accordance with standard piping practices (see 6.2).

Expansion joints most often are custom engineered and fabricated for specific applications. Because there is an infinite number of sizes that might be required for use in piping systems which include both standard and nonstandard sizes, specific sizes are not cited in the classification paragraph of this specification (see 1.2 and 6.2).

Packed joints have slip-tube guides provided both on the internal (pressure) and external (atmospheric) side of the packing chamber. The external guide is either integral with or rigidly attached to the body. The packing for this joint is the semiplastic type which can be added while the joint is under full line pressure. To completely repack the joint, however, the service must be shut down.